Field of the Invention
The present invention relates to a processing apparatus for processing a plate-like workpiece held under suction by a chuck table while supplying processing water to the planar workpiece.
Description of the Related Art
Cutting apparatus for rotating a cutting blade and forcing the cutting blade into a plate-like workpiece such as a semiconductor wafer or the like to cut the plate-like workpiece use a chuck table for holding the plate-like workpiece under suction. The chuck table employs, as a suction source, an ejector for attracting the plate-like workpiece under a negative pressure that is developed when air flows (see, for example, Re-publication of PCT International Publication No. 2005-3043).
Processing apparatus that process a workpiece with a grinding wheel such as a cutting blade or the like, as is the case with the above cutting apparatus, use processing water for cooling the grinding wheel. During operation, the processing water finds it way between the upper surface of the chuck table and the lower surface of the wafer, and is drawn in by the chuck table. The processing water thus drawn in obstructs the flow of air from the ejector, tending to lower the suction force generated by the chuck table. One solution to the problem has been proposed to insert a separator in the pipe that interconnects the chuck table and the suction source, for separating the introduced processing water to prevent the suction force from being reduced (see, for example, Japanese Patent Laid-open No. 2014-34068 and Japanese Patent Laid-open No. 2012-151263).